It has been discovered that the medical outcome for a patient suffering from severe brain trauma or from isehemia caused by stroke or heart attack is improved if the patient is cooled below normal body temperature (37.degree. C.). Furthermore, it is also accepted that for such patients, it is important to prevent hyperthermia (fever) even if it is decided not to induce hypothermia. Moreover, in certain applications such as post-CABG surgery, it might be desirable to rewarm a hypothermic patient.
As recognized by the present invention, the above-mentioned advantages in regulating temperature can be realized by cooling or heating the patient's entire body. Moreover, the present invention understands that since many patients already are intubated with central venous catheters for other clinically approved purposes anyway such as drug delivery and blood monitoring, providing a central venous catheter that can also cool or heat the blood requires no additional surgical procedures for those patients. However, single purpose heat exchange catheters such as are made by Innercool Therapies of San Diego, Calif. and Zoll Medical Corp. can also be less optimally used.
Regardless of the particular catheter used, it is clear that heat must be removed from or added to the coolant that flows through the catheter. As still further understood by the present invention, it is desirable that the heat exchange system be easy to use by health care personnel, and provide for monitoring systems and convenient temperature control. U.S. Pat. No. 6,146,411, incorporated herein by reference, discloses one such heat exchange system.
As understood herein, it would be advantageous to test the heating/cooling system to ensure proper functionality regarding the ability of the system to cool or heat the glycol liquid that in turn will heat or cool the saline liquid being used in the catheter.